Multiplier unit and supporting means



Feb. 1, 1949. FQRGUE 2,460,381

MULTIPLIER UNI'I AND SUPPORTING MEANS Filed Feb. 7, 1946 '3 Sheets-Sheet 1 IN VEN TOR.

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MULTIPLIER UNIT AND SUPPORTING MEANS Filed Feb. 7, 1946 3 'Sheets-Shqet 3 {a v l Q R x I K II Q . & I Q t l I "ll I I J! 1 R an a I BY Z 2 2 k Q .a' N v Q W A jam-:v

Patented Feb. 1

MULTIPLIER-UNIT AND screens-rise MEANS Stanley V. Forgue, Granbury, N., J" assief lio f i Radio Corporation of America a corporation of;

Delaware 'sp licsii nsebrusiy v 1 46; Se al o- 6 6 615 6 Claims.

is inv ri i e ates, to m t ier uni s, f r te evision pick-up ubes sueh disclosed, or example, n t e appli at n f Paul W imen, filed September l6, 1944, Serial No. 554394, U. 's, Patent 2,433.,ee1, issu d January e, 1948,

and means 'for supporting the units within the tube as a rigid assembly to and around the cathe Ode gun.

It is an object of the invention to mount the parts of a multiplier unit together by stamped fOther objects oi the invention will appear in the following description, reference being had to the drawings, in which: 4 V v Fig. 1 is an elevation of the spacing wheel used i the multiplier unit.

Fig. 2 is an elevation of the clamping ring. Fig, 3 is a section taken on the line 3-.3 of Fig. 2.

ig. 4 is an'elevation of the bushing.

Fig. 5 is an elevation of the pinwheel dynode of the multiplier unit, only a few of the blades heing shown 'to simplify the illustration.

Fig. 6 is an'edge view of the Pinwheel, two blades, only, being shown, the others being omits ted to simp i y e illus ra e i 71s a ct onal elevat on i he assem led P ts e e mu iplie n t k n on a di m ter of the circular parts,

Fig 8 is an elevation of the multiplier disc cont tu i the fin l d nod oi heri of m lt p e so e I Fig. 9 is a sectional elevation of the assembled parts of the final multiplier stage, taken on a, ame er of th circula pa ts. 7 Fig. 10 is an elevation of multiplier units ass mb on the sun o a ath e y tube i lustrating the method of mounting in relation to the gun and other parts of the tube,

Ref ring to F ss- 5 and 6 o the draw n the Pinwhe l dy e e I ispahticu arly di cl d said applicatio of l :K. W m r and e d o be, d s se in m ete e ail he in as t is net claimed. and i hot Pa o hi in en -10h ex p er t e mehn ref omehntin th rts It may he sa howe er, a the Pinwhe l is st mp d fr m. s hin: she t hi silveragnesium and is circular n fo m with a pl ra ty of van s? @nQQ t is somewhatsimilar to an electric; ian. When a series of these units is used in a tube a in Fig. 1 o e i w vhas b d xt ndi to th right, a hfie. 6, and the next u t a Pinwheel with the blades extending to theleit and so on, The electrons strike against these blades when used in a cathode ray'tubeto produce secondary emission, the eleetrons of which are attracted toward and impinge against the next dynode. The thin sheet metal from which the dynode'is made is clamped at its periphery around a circular Nichrome ring 3 and at its center part the metal is stamped to provide a, small circular hub 4 having a bore to fit in spaced insulated relation over the gun, generally indi.-. es a 5 n ,1 n thi feu' 6 ind ates the first anode having an end surface I constie. tuting the first dynode. of the multiplier, The grid is indicated at 8 and the cathode at 9. Core tain parts are broken away to show these eleo trodes. ,o

A wheel ill is stamped from thin sheet Nioh eomeiFig. 1 with a minimum number of spokes II between the inwardly extendin flange o h o te rim !2 nd, t warellyten in fla ge e h s e a s h s A fine c en I 4 ei eu e term with a i met r in excess oi the diameter oi the spoked wheel In i ada ted o h lamhedkb tw e i the ehfie. en e m of h heel yth fishes 5 m the h ed t i t is "5! as shewe in Fife 7 Tales H on the im I 6 a adeleted to e urned ai the inwheel when theother parts are assembled th The sereen h lds hedyned bl des 2 r from P e e n pe els while p mittin most of h ele ons 9 P ss thr u th m hes is mba the P he l blad s ,2 wit m nimum hitt g f thene ste lels 9 he ereez-t em ases t s d sire e to urn thesespelees 0"! se t t the wi l h deewise to he eleetreh eam Th cre n ill-si ee ht al pehiee of smaller diameter 'fthanthe. opening in hub l3 e he pok s whe A (sens d us in t 9i t h. Niehreme m ta ha an outsi e d ame er differing from the inside diameter oi the l 3 by about twice the thicknessoi the thin screen [4. V V

- In assemblingthe parts as illustrated Fig, '7, t e im s esse o e sheke Wheel '9 vs9 t e perip ery of t e sere h is n n wedged therebetween. The bushing i3 is placed so a to emh he ner e eei t e se eeh I! against the hub 13 of the spoked wheel In If des red. the rim '5 and. ri of w el t may he h t de tes ei t roug the s ee and the hub 13 and bushing i8 may be similarly spot welded. The pinwheel I, with the blades extending inwardly of the assembly, is placed in position so that its bead fits inside the rim I6 and against the edge of rim i2 and its hub 4 fits inside the bushing i3. When the parts arein this position, as shown in Fig, '7, the tabs H are bent inwardly against the pinwheel i. The parts of the multiplier unit are then held firmly in assembled po sition.

The final or fifth dynode, as shown is not of the pinwheel type, It consists of a circular silvermagnesium disc I9, the periphery of which is wrapped around a Nichrome ring 28. This disc has a central hole to fit over the gun when in assembled position. The dynode disc is placed inside the rim iii of the ring l5 (Figs. 2 and 9) and a retainer ring 21, like the wheel of Fig. 1

except the spokes are omitted, is abutted against they head of the disc [9. The tabs H are then bent. down against this ring to hold the parts together. 7

; The collector electrode consists of a fine mesh screen like the shield screen of M. This electrode. when mounted, is exactly like the assembly shown in Fig. 7 with the pinwheel removed. The tabs H are then bent down against the rim of spoked wheel [0.

The fifth multiplier stage 22, the collector stage 23, the fourth multiplier stage 26, the third multiplier stage 25 and the second multiplier stage 28 are assembled over the gun 5 in the order mentioned before the end i, which is the first mu1tiplier stage, is mounted in the first anode cylinder 6, as disclosed in my co-pending application, filed January 28, 1946, Serial No. 643,925, now U. S. Patent 2,441,315 issued May 11, 1948. Alternate ones of the pinwheel dynodes have the blades bent in opposite directions to better intercept the electrons, as already explained.

The, multiplier units are supported on a plurality of ceramic tubes 21 in which are conducting wires 28 for supplying potential to various electrodes. The units are fastened to the tubes by U-shaped straps 23, welded to the rims l6. These are bent around the tubes and the ends welded together. These tubes support the cylindrical base 39 by means of U-shaped straps 3!. The gun 5 is assembled and mounted on the base, 30, as disclosed in my said application.

A potential ring 32, commonly called a persuader, is also mounted on the insulation tubes 27 by'straps 29. A potential cylinder 33 is also secured to the tubes by means of U-shaped straps 34. This cylinder has the function of and displaces the usual wall coating. Other electrodes, such as the target, decelerator and photocathode ring, shown in said Weimer application, may be supported on the tubes 27, shown broken off at the right in Fig. 10. The wires 28 are also shown broken off at the left of Fig. 1. They are to be welded to lead-in rods at the base of the tube. This is not part of my invention and is not shown.

Spring snubbers 35 are welded to the wires 28, as at 36, or to the electrodes, as at 3'5, and the free ends extend in arcuate position, so that when the complete unit is assembled inside the tube these snubbers will contact with the glass envelope to resiliently support one end of the complete assembly inside the tube, the other end being supported by the lead-in rods.

The connectors for supplying potentials to the variousdynodes and other electrodes are not 4 7 shown, as connections may be made in wellknown ways.

The number of multiplier dynodes has been given by way of example, only. More or fewer multiplier stages, of course, may be used and various other changes made without departing from-the scope of the'invention.

The operation of the multiplier is described fully in said Weimer application, but it may be said briefly that the beam electrons returning from the vicinity of the target strike the surface of the first dynode i and bombard secondary electrons therefrom. These are directed by persuader 32 into the second multiplier stage 26, where they hit the surface of the pinwheel blades 2 and bombard secondary electrons therefrom. The screen I4 of Fig. 7 permits the primary electrons to pass through to engage the blades, but it screens the secondary electrons from preceding potentials and these are attracted through the spaces between the blades through the shield screen of the next multiplier stage, where they bombard secondary electrons from the blades therein. This continues until the secondary electrons bombarded from the final stage 22 are attracted to the screen collector stage 23 and the current passes therefrom to the output'terminal of the tube (not shown).

I claim:

1. A multiplier unit for television transmitter tubes comprising a metal wheel having an outer rim with an inwardly extending flange, a, hub with a bore and an outwardly extending flange and spokes connecting said flanges together, a fine mesh metal screen. having an opening adjacent said bore, a ring having a band and an 'in wardly extending flange pressing said screen against said rim and the first-mentioned flange, and a bushing in said bore having an outwardly extending flange, said bushing pressing said screen against the circumferential wall of said bore and the flange of said hub, a portion of said ring being bent inwardly for holding said wheel and screen together therein.

2. A multiplier unit for television transmitter tubes comprising a metal Wheel having an outer rim with an inwardly extending flange, a hub with a bore and an outwardly extending flange and spokes connecting said flanges together, a fine mesh metal screen having an opening adjacent said bore, a ring having a band and an in wardly extending flange pressing the outer edge of said screen against said rim and the first-mentioned flange, a bushing in said bore having an outwardly extending flange, said bushing pressing the inner edge of said screen against the flange of said hub, and a multiplier dynode having an outer rim seated within said first-mentioned-rim, a portion of said'ring being bent inwardly for holding 'said wheel, screen and dynode together thereinagainst the inwardly extending flange. I r

3. A multiplier unit for television transmitter tubes comprising a metal wheel having an outer rim with an inwardly extending flange,- a hub with a bore and an outwardly extending flange and spokes connecting said flanges together, a fine mesh metal screen having an opening adjacent said bore, a ring having a band and aninwardly extending flange pressing the outer edge of said screen against said rim and the first-mentioned flange, a bushing-in said bore having an Outwardly extending flange, said bushing pressing the "inner edge :of said screen against the circumferential wall of said bore and the flange of said hub, and a multiplier dynode having an outer rim seated within the rim of said wheel and a hub extending into said bushing, a portion of said ring being bent inwardly for holding said wheel, screen and dynode together therein against its inwardly extending flange.

4. A multiplier unit for television transmitter tubes comprisin a metal wheel having an outer rim with an inwardly extending flange, a hub with a bore and an outwardly extending flange and spokes connecting said flanges together, a flne mesh metal screen having an opening adjacent said bore, a ring having a band and an inwardly extending flange pressing the outer edge of said screen against said rim and the firstmentioned flange, a bushing in said bore having an outwardly extending flange, said bushing pressing the inner edge of said screen against the circumferential wall of said bore and the flange of said hub, a multiplier dynode having an outer rim seated within the rim of said wheel and a hub extending into said bushing, and tabs on said ring for holding said wheel, screen and dynode together therein against the inwardly extending flange.

5. A multiplier unit for television transmitter tubes comprising a metal wheel having a peripheral member, a hub with a bore and spokes connecting said hub and member together, a fine mesh metal screen having an opening adjacent said bore, a ring pressing said screen against said peripheral member, and a bushing in said bore pressing said screen against the hub to hold said wheel and screen together.

6. A multiplier unit for television transmitter tubes comprising a metal wheel having a peripheral member, a hub with a bore and spokes connecting said hub and member together, a fine mesh metal screen having an opening adjacent said bore, a ring pressing said screen against said peripheral member, a bushing in said bore pressing said screen against said hub, and a multiplier dynode having an outer rim seated within said first-mentioned rim, said member clamping said wheel screen and dynode together.

STANLEY V. FORGUE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,183,309 Flechsig et a1 Dec. 1 1939 2,213,174 Rose Aug. 27, 1940 2,217,198 Davisson Oct. 8, 1940 2,433,941 Weimer Jan. 6, 1948 

